Transistor



April 16, 1957 'I'RANSISTOR Filed April 14, 1954 6. VAN DONKRSGOED ETAL2,789,257

INVENTORS LEONARD JOHAN TUMMERS GERRIT VAN DONKERSGOED AGEN T UnitedStates Patent G TRANSISTOR Gerrit van Donkersgoed and Leonard JohanTummers,

Eindhoven, Netherlands, assignors, by mesne assignments, to NorthAmerican Philips Company, Inc., New York, N. Y., 21 corporation ofDelaware Applieation April 14, 1954, Serial No. 423,978

Claims priority, application Netherlands May 26, 1953 4 Claims. (Cl.317-235) The invention relates to a transistor consisting of asemi-condnctive body comprising two electrodes arranged on oppositesides.

It is known to arrange such a semi-conductive body made, for example, ofn-type germanium to be very thin at a point at which two pointelectrodes are arranged opposite each other. It has also been suggestedto make one of these point electrodes from a deterrnined metal, forexample gold, and to subject the transistor to a determined currenttreatment with the resultant advantage that the crystal need notnecessarily be so thin and consequently that its manufacture isfacilitated.

However, in these known transistors it remains necessary to ur ge thetwo point contacts to opposite sdes of the semi-conductive body so as toregister exactly with the result that its assembly is more diflicultthan that of a transistor comprising two point electrodes arrangecladjacent each other.

A further disadvantage which is also of a structural nature consists inthat the dimensions of a transistor comprising two points arrangedopposite each other are comparatively large and widely different fromthe dimensions of the normal transistors comprising two adjacent points.

According to the invention, the object of which is, among ether things,to obviate these disadvantages, the transistor consists of asemi-conductive body to one side of which an electrode is sealed whilsta point electrode is arranged on the opposite side.

In a preferred embodiment the transistor is arranged in a marmer knownper se in a cylindrical metal casing which on one side comprises twocontact stads.

In an alternative embodiment the transistor is arranged over a base inwhich in a manner known per se three contact studs are arranged parallelto each other, the point electrode being arranged parallel to the base.

The invention will now be descn'bed with reference to the accompanyingdrawing, in which two embodiments thereof are shown by way of exarnple,and in which Fig. 1 is a perspective view of a transistor of the typecomprising a cylindrical casing;

Fig. 2 is a vertical cross-sectional view of such a transistor, and

Fig. 3 is a side view of a transistor of the type comprising a baseprovided with three studs.

The transistor shown in Figs. 1 and 2 consists of a semi-conductivemono-crystal I made up, for example, of n-typc germaniurn to the bottomof which a small amount of iridium 2 is sealed or fused. Due to thediffusion thereof into the germanium, the latter is locally convertcdinto p-type material. A point electrode 3 is arranged on top of thecrystal. Due to the comparatively exten 2 sive junction, i. e., therelatively largearea rcctifying connection, between the electrode 2 andthe crystal 1, the position of the electrode 3, which provides arelatively smallarea rectifying connection to the crystal 1, can bechosen wthin wide lmits so that it is aligned with the electrode 2 andthus its assembly presents little dificulty.

The crystal 1 is secured by soldering between two nickel strips 4 whichin turn are secured in a cap 5 and which constitutes a base ohmicconnection to the crystal 1. This cap is clamped in a tubular casing 6.An insulating plug 7 comprising two contact studs 8 and 9 is clamped inthe upper end of the casing. The stud 8 carries the point electrodewh.ilst the stud 9 is hollow so as to permit a wire 10 which is solderedto the electrode 2 to be passed through this stud. Thus, this wire canbe shortened when the point electrode 3 and the crystal 1 are broughttogether; when these parts have been moved into position the wire 10 issecured by soldering at 11.

This transistor can be dimensioned so as to perrnt its beinginterchanged with a usual transistor comprising two points. Thetransistor shown in Fig. 3 is shaped into a different form. t is builton an insulating base 15 comprising three adjacent studs 16, 17 and 18.

A semi-conductive crystal 19 is secured to a stud 17 by interposition ofa nickel strip 2i, which oonstitutes the base connection. A diiusionelectrode 21 is connected to a stud 16 by means of a conductor 22. Thepoint electrode 23, which is substantially aligned with the dilrusionelectrode 21, is secured to a stud 24 which is clan1ped in an eyelet 25so as to be able -to move therein, which eyelet is arranged on a tubularmember 26. This member is in turn capable of moving over a contact stud18. Thus the point electrode is easily adjustable.

The entire transistor is embedded in an insulating mass 27 shown by abreken line and engaging the base 15.

Since in this transistor only one point contact is provided, theaggregate can be dimensioned so as to permit this transistor to beinterchanged with the known type of transistor comprising two diffusionor fused contacts.

What is claimed is:

1. A transistor comprising a semi-conductive body, a base ohmicconnection t-o said body, and two rectifying conncctions to oppositesides of said body and substantially aligned with each other, one ofsaid rectifying connections comprising an electrode fused to and diffused into said body producing a relatively large-area junction, theother of said rectifying connections comprising a point electrode incontact with said body pro ducing a relatively small-area junction.

2. A transistor comprising a cylindrical metal hous ing including a pairof spaced terminals electrically connected to the housing, asemi-conductive body rnourrted between said terminals and forming anohmic connection therewith, a pair of electrodes within said housing andinsulated from each other and from the housing, ons of said electrodesbeing fused to and diifused into one side of said body and formng arelatively large-area rectfying connection thereat, the other of saidelectrodes fori ing a point contact with the opposite side of said bodyand a relatively small-area rectifying connection substantially alignedwith the large-area rectify=ing connection.

3. A transistor as set forth in claim 2 wherein the semioonductive bodyextends at right angles to the axis of the housing, and an insulatingplug secured to the housing supports the two electrodes.

4. A transistor comprising a base member, a semiand a point electrode incontact With the oher Side of said body and producng a relativeysmall-area rectfying connecton aligned with the relatively large-areaconnection, sad pont electrode extending substantially paralle1 to thebase, said electrodes beng supported on said base.

References Ctedn thefile of. this patent UNTED STATES PATENTS Pfann July24, 1951 Wallace Aug. 7, 1951 Sparks Feb. 24, 1953 Kinman Mar. 31, 1953Gaudlte Mar. 2, 1954 Stan et al June 1, 1954

